Introduction
Power improvement products are not easy for average consumers to get their minds around. There are many different philosophies on how to do it right, with few agreeing on what’s best. Questions on power correction come my way quite often, with most people wondering if they even need better AC and, if so, how much they need to spend to fix the problem.

To exacerbate the issue, bad power is not always something that you hear and can determine needs improving, but rather an area that, once you correct it, you’ll wonder why it took you so long to fix.

The Transparent PowerIsolator 8 is a reference-level power-conditioning device that provides eight hospital-grade outlets for your precious AV gear. It is available only in a black-brushed finish and retails for $2,995. The Transparent PowerIsolator 8 is a much sleeker-looking product than Transparent conditioners of past. The PowerIsolator 8 measures a slim 2U rack height of three-and-one-half inches tall by 17 inches wide and 19-and three-quarters inches deep. It comes complete with separate rack-mounting ears, in case you are so inclined.

The front of the unit has a rich-looking brushed machined plate with a tapering beveled edge that runs across the top and bottom of the bezel. At the center is a long window. Underneath are three LED lights indicating “Protection Active,” “Line Fault,” and “Isolation Active.” In the darkness of my room, I could see two green LEDs and faint red text reading “Transparent PowerIsolator 8.” The PI8 is packaged very well and is as solid as a block of metal. The fit and finish of this unit are outstanding, making the PI8 a welcome addition to my rack. At the back of the unit are four pairs of isolated outlets and a standard IEC power cord connector. The unit sits on four rubber feet, in case you choose to forego the rack-mounting and decide to shelf or stand-mount.

Technology
When it comes to technology, each company has its own spin on what
makes power perfect. The problem is that electrical engineers who are
not always music aficionados tend to design most power products.
Therefore, what is supposed to be perfect on paper is not always the
best-sounding solution. For this reason, I recommend that you don’t get
completely caught up in all the techno mojo, but rather give the best
products a listen when practical, and choose what sounds best to you.
Often, it’s the simpler designs that win the battle of sound.

Let’s talk about a couple issues that degrade AC power. Perhaps the
biggest is the noise that is generated from household appliances. These
can add significant noise to your line and degrade your AV experience,
smearing your soundstage and rendering your micro-dynamics, transients
and decay inaudible. To makes things worse, it doesn’t even need to be
your own household’s appliances, as noise will transfer across the
power lines. Most people have heard recommendations to install
dedicated power circuits in their home for their AV gear. Although this
is the best non-conditioned option, and it may give you more consistent
power, it will not remove most of the noise from the line. The fact is
that unconditioned power is always an issue. The only question is, how
much of an issue is it in your home?

There are a few different ways to combat these anomalies. Some choose
to regenerate power by comparing the incoming current to a reference
sine wave, and using an amplifier to recreate the wave. Although this
has many benefits, it also has issues, one of which is that you have
just reintroduced another amplifier into the line, one of the noisiest
components in a system. These units can get hot, are large and consume
energy; in some cases, they utilize tremendous amounts of power.

Another philosophy is power regulation. This can serve to ensure there
is always adequate current, yet it can be argued this does little,
because if your components see lower voltage, their power transformers
simply reach out and get more current. Another method is to filter the
line. This can be the least expensive method, yet it often provides the
worst results. Bad filtering will cause compressed dynamics and the
complete smearing of your precious soundstage.

You must be very careful when auditioning power-related products, due
to the fact that most, if not all, have positive attributes as well as
negatives. You will often hear improvements in one area and degradation
in another. For example, the midrange could be much improved, giving
you the impression that your sound is better, yet your dynamics and
bass response may be less defined and far less solid. Transparent has
taken a new approach to this age-old issue. Transparent’s PowerIsolator
8 employs an all-parallel circuit construction with all the electronic
components placed in parallel and no noisy printed circuit boards.

The PowerIsolator 8 provides eight outlets, or four pairs, each pair
having complete noise isolation. What this means is that you can plug
in your noisy digital gear, as well as sensitive electronics like your
AV preamp and amplifiers, without noisy cross-talk, something that most
power products do not provide. Additionally, the PI8 provides complete
surge protection without the considerable drawbacks you can expect from
the units at your local office supply store.

Background
For close to two decades, Transparent Audio has been manufacturing
audio and video cables at the very highest performance level. I have
used their speaker cables and interconnects, as well as their premium
video cable, in my reference system for close to 10 years. I spent many
years auditioning cables and settled on what I feel is the
best-sounding cable money can buy. Currently, I am running Transparent
Reference speaker cable and Reference interconnects. As for power, I
have reviewed everything from PS Audio and Audiophile APS to Exact
Power and many more, and have been referencing the Transparent
PowerIsolator 4 since Ed Masterson’s favorable review back in April of
2003. In my system, the PI4 is one of the best-sounding AC products,
albeit one of the lowest-tech, I have heard. The question remains, does
the PI8 improve upon the PI4 of past?

Set-up
For the evaluation of the Transparent PowerIsolator 8, I focused on
three distinct conditions, the first being untreated power coming from
my wall. I’ve found my untreated AC to be very average, having heard
both better and worse. The easiest way to evaluate the condition of
your untreated power is to measure the level of improvement you achieve
from AC conditioning: it’s that simple.The second set-up was with the
use of my longtime reference, the Transparent PowerIsolator 4. Lastly,
I connected the PowerIsolator 8 and auditioned the same musical pieces.
The music I selected was based on subtle nuances that could be achieved
with power improvement.

Music and Movies
Yes’ multi-channel DVD-Audio version of the classic Fragile (Warner) kicked off my evaluation. I started with the first cut, “Roundabout,” which is one of the all-time great progressive rock compositions. This song starts with a harmonic pluck of the guitar string, followed by another harmonic strum. After playing this intro several times with untreated AC, it was time to connect to the Transparent PI4. I connected my Mark Levinson No.436 monoblocks, the Proceed HPA3 that drives my center and rear channel speakers and my Meridian G98/G68 player and preamp.

The first thing that I noticed was the absence of any notable noise. The instruments were more present, as if they stepped from behind a curtain into my listening area. The harmonic decays were considerably more detailed and natural, with much more depth, and the size and width of the room were all the more apparent. Jon Anderson’s voice had a more natural texture and again there was more information. Perhaps the biggest difference was in the air surrounding Anderson’s voice and accompanying instruments. After switching to the PowerIsolator 8, there was an immediate difference. The first thing that I noticed was that the already lowered noise floor from the PI4 was again improved. Perhaps most surprising was how much more natural Howe’s guitar had become. When we evaluate components, we talk about detail and soundstage prowess. Often overlooked is the sheer palpability and sweetness of the instruments being reproduced. Howe’s 1953 Martin 00-18, a small-body acoustic guitar known for its immediate attack and superb projection, was closer to me than it had ever been before. This level of improvement was outstanding. I could almost smell the tone-woods in his guitar.

There was improved decay brought on by the complete absence of background noise. This is something that I found again and again throughout my evaluation. In the song “The Fish,” Chris Squire’s bass lines were more distinguishable than I had heard from the PI4 and untreated AC tests. During this song, there are a lot of things going on all at once and the low drawl from Squire’s bass can get lost in the mix. Initially, I wasn’t sure this was possible and A-B’d this piece a few times before I concluded that the bass had a more immediate presence; it was the leading and trailing transients that were providing the necessary detail to bring this instrument out from relative obscurity. The PowerIsolator 8’s ability to delineate such subtle low frequency information proved to be amongst its strongest assets.

To test for vocal purity, I selected Alison Krauss’ 1995 release, Now That I’ve Found You: A Collection (Rounder Records). Although Krauss’ record is usually found in the country music section of your local retailer, her voice is so pure and inviting that it transcends far beyond this genre label. Having owned this CD for the better part of 10 years, I’ve heard it on many of the components that I have evaluated and every power product I’ve reviewed. Stepping back to wall-power, I first listened to the song “Oh, Atlanta,” one of purist vocal cuts I own. Changing to the older Transparent PI4, there was improvement very typical of earlier evaluations. There was reduced noise and grain and, simply put, more audible information. Krauss’ voice took on a new life and imaging was much tighter. With untreated power, her voice was well located and concentrated, yet with the PI4, her voice was considerably more focused. Again connecting through the PI8, her voice amazingly took on a whole new level of focus. Perhaps the most impressive part of this cut is the acoustic guitar solo. Although simple in nature, the PowerIsolator 8 was able to delineate the subtlest changes in texture and strumming attack. This level of improvement proved to be absolutely infectious. This was undoubtedly the most impressive audition of this cut that I have heard on any system anywhere. It quickly became obvious that Transparent’s less-is-more design philosophy had clearly succeeded in producing the finest-sounding AC power product that I have heard to date.

It is difficult to evaluate not only specific aspects of your music, but also the overall spectrum of the music from top to bottom. Many AC products improve areas of your music, but supply less than desirable qualities in other areas. The Transparent PowerIsolator 8 improved every aspect of my music. It provided separation between instruments, but moreover, it provided much greater instrument decay, which physically brought the instruments into my room. We’ve all heard it before: “It was like they were standing in my room.” With the Transparent PI8, Alison Krauss was literally breathing on me.

Switching gears, I loaded up DTS’s 2006 demo disc Alive! (DTS Digital Entertainment). This DVD has a series of short clips from well-known movies and serves as a great demo for anxious guests. The segment from “Fantastic Four” (20th Century Fox Home Entertainment) serves up some extreme high and low frequency information. It showcases the scene where Thing (Michael Chiklis) runs into a distraught and suicidal man on the bridge. When this man sees the orange rock-like figure, in a moment of panic, he falls down on the deck of the Brooklyn Bridge during daytime traffic. Thing drops down to protect him and takes the impact of a semi truck as it folds around him, followed by a multi-car pileup. Again, I ran through the three different power scenarios, finishing with the PowerIsolator 8. The difference in detail was very similar to that of my music evaluations. The low-frequency information became more legible and had much greater impact. There was a huge difference in clarity, which gave the scene an eerily lifelike impact that had me riveted to my chair. The sounds of crunching metal and breaking glass were abundant and crystal clear. I found the center channel information to be particularly improved. There was the slightest of grain with untreated AC that was long gone with the PI8.

I wanted to test for any potential improvements in my video picture when plugged in to the PowerIsolator 8. I plugged my Vidikron Vision 2 eight-inch CRT projector into one of the PI8’s isolated outlets. I project onto a 76-inch-wide Stewart Filmscreen Studiotec 130. This projector is known for its extreme black levels and filmlike picture. With the PI8 in place, the picture was indeed improved. There were improvements to the edge detail, making images look much more 3D. Although black levels were improved, this change was small but nevertheless alluring. Colors were perhaps the most improved, as such films as “Moulin Rouge” (20th Century Fox Home Entertainment) provided eye-widening candy-like colors that had my guests in awe. The moral of this story is simple: if you own an expensive video device, it deserves this level of improvement.

The Downside
The PI8 does about everything you can ask from an AC power-conditioning product, if improved performance is your primary concern. One knock I can point out is that the PI8 will protect you from surges and spikes, but it doesn’t have any form of battery back-up to protect components like your digital projector from sudden power outages, which potentially can destroy your expensive bulbs.

Conclusion
Untreated AC power is robbing the performance of your quality AV components and, as much as you want this to be someone else’s problem rather than yours, most likely there is no such luck. Exactly what level of improvement you’ll achieve depends on how bad your incoming power is. The results that you can expect to see will likely parallel my findings.

The Transparent PowerIsolator 8 provides complete surge protection without the typical drawbacks you see from commercial surge products. This will be particularly welcome in high-risk areas of the country. Because the PowerIsolator 8 has four pairs of noise-isolated outlets, you can connect your digital players and amplifiers without fear of cross-talk and noise transfer. Other products recommend that you don’t mix them, limiting what you can actually connect without degradation.

With its simple cosmetics and superb build quality and performance, the PowerIsolator 8 is my choice to compliment my reference system. As you can tell by the components that I possess, I demand the very best money can buy and the PI8 is exactly that. If you are looking to improve the performance of your AV gear and want a product without compromise, give the Transparent PowerIsolator 8 a listen in your home. And when you do, go ahead and clear a spot in your rack for the audition, because the PI8 is not likely to leave.